Because of the present day "information explosion", data are being accumulated at such a rapid rate that compact data storage systems are becoming ever more important. One of the most satisfactory data storage systems thus far devised is that of microfilming, wherein sheets of data, reports, books, blueprints, pictures and the like are photographed in a photographically reduced size. Typically, an entire page then requires an area of about one half inch by five eighths of an inch. These reduced size frames are then suitably assembled. This system results in a tremendous compaction of storage space requirements.
One of the early methods of assembling these reduced size frames was to position them tandem-wise, on a reel of film, but this system had the disadvantage that it became difficult to have access to a single frame without somehow going through every frame that preceded it on the reel.
Another method of assembling the reduced size frames was to print related frames onto a given sheet of film, and this became known as microfiche. In using the microfiche, a single frame is more readily retrieved when desired, providing random access to the desired frame.
The microfiche, during its evolution, has taken a number of different sizes. One of the most popular sizes is about 6 inches long and about 4 inches wide. This size of microfiche may be designed to contain from about 60 to over 400 frames. Other sizes are also in use. The diversity of microfiche has hindered the storing and retrieval of microfiche stored data.
An attempt at retrieving microfiche involved attaching a notched metal clip to one edge of the microfiche, the notches being coded for use in data retrieval. Another arrangement wherein the edge of the microfiche includes coding formed by a series of holes and notches is shown in U.S. Pat. No. 3,831,749. Some other arrangements used optical approaches and still other arrangements used markings to produce a frequency signal.
The main disadvantage of the foregoing arrangements was that they required additional equipment and procedures for manufacturing each type of microfiche. Since each arrangement required different retrieval apparatus, it was extremely difficult to intermix microfiche from different sources.
Another microfiche carrier is disclosed in U.S. Pat. No. 3,807,074 assigned to the same assignee. As shown therein, the carrier takes the form of a plate having a transparent portion adapted to receive a microfiche. The carrier plate may be formed by producing a pocket in a sheet of transparent material. The resultant microfiche carrier is a relatively rigid plate containing a microfiche positioned in its transparent portion.
A cartridge or magazine for microfiche is disclosed in U.S. Pat. No. 3,991,497 assigned to the same assignee as the present invention. As shown therein, the magazine comprises a pair of side walls, each of which is formed with an elongated arcuate protrusion, a top, a bottom and a front wall having a window therein. The back of the magazine is open to receive a deck of microfiche carriers. Each of the carriers is provided with detent means which coact with the arcuate protrusions for releasably holding the microfiche carriers in place in the magazine, and coding tab means adapted to be acted upon by pusher means for partially ejecting a selected microfiche from the open back of the magazine.